adding sag to solid state rectified amp w/ resistors

[music321]

When using resistors in series with a solid state rectifier, to mimic the sag of a tube rectifier, how closely is the tube sag approximated? Is the result pretty good, or is it just a "passable" workaround?'

I wonder, because I'm thinking an amp with a solid state rectifier, and a resistor that can taken in or out with a switch might be worthwhile.